To be the nephew of the great artist, anatomist and inventor Leonardo da Vinci might have been very exciting, particularly when young Leo, at the age of just thirteen, was sent to study as his uncle's apprentice in Florence, Italy. Leo, however, was not altogether happy at having to leave his home and his friends in Venice.

But Leo was heading for more excitement than he could have possibly imagined. His uncle's latest invention, not yet working properly, was due to be presented to the King of France as part of negotiations to ensure peace. Unfortunately for Leo and his uncle, not everyone wanted peace, and there were those who will go to any lengths to stop them. Leo and his uncle were in danger, and failure could have disastrous consequences for both of them and for Italy.